Hello Mohammad, if you use same concentration of your substances and same method (number of scans etc), you should be able to get comparable results. You could also add an internal standard to calibrate the spectra.

Thank you Maksim and yes! but at what intensity you should show your work? how can you make sure all the spectra are in the same intensity level? there is an option in Mnova for normalizing the intensity based on a specific peak or largest peak etc. I was wondering is there any one used that? and again is there any systematic way to make sure the intensity levels of all the spectra are the same. cause you can easily play with mouse scroll and change the intensity.

I came up with this procedure:

In Mnova software under processing tab there is normalize... option. when you click that you can select to normalize your spectrum based on largest peak, peak area or peak, etc. I selected a peak that it was similar in all of my spectra and then you can select a value for that peak which will intensify that specific peak and normalize your data based on that peak. I did that for all of my spectra and after that when you stack your spectra it will show the normalized spectra and in the stacked form you can increase/decrease the intensity of all the spectra at the same time. This procedure seems reasonable to me.

I asked several people and they said that they normalize the intensity by just trying to make the intensity for different spectra look the same for a specific peak manually and by just looking at the peaks and changing the intensities which is very subjective. Therefore I think this procedure that I proposed is a better option. Please let me know if you have any suggestions.

and I know and understand that when you run all of your samples with same NMR parameters and conditions they should look the same but normalizing the intensity I think is always good to make sure everything is leveled.

Thanks